Inviscid Unsteady Aerodynamic Model of Airfoils Moving Near Boundaries
Open Access
- Author:
- Sen, Nilanjan
- Graduate Program:
- Mechanical Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- None
- Committee Members:
- Christopher Rahn, Thesis Advisor/Co-Advisor
- Keywords:
- Aerodynamic model
Conformal mapping
Potential Method
Clap-and-fling - Abstract:
- There is considerable interest in the development of flapping wing Nano Air Vehicles (NAVs) for military applications. These NAVs operate in the Reynolds number regime 10^2-10^4 which is similar to the Reynolds regime of small insects. It is important to understand the aerodynamics of flapping wing flight in this regime in order to build high performance NAVs. Aerodynamic models that can predict the flow and associated forces are a useful tool to understand flapping wing mechanisms. The Weis-Fogh clap-and-fling mechanism, is used by certain insects operating in the low Reynolds number range (10^2). The Weis-Fogh mechanism generates additional lift compared to conventional flapping wing mechanisms and is therefore advantageous to use in NAVs. This thesis presents a two-dimensional, non-linear, unsteady aerodynamic model of an airfoil in a bounded domain. Key concepts of flapping wings such as leading edge vortices and wing-wake interaction are included in the model to provide a better prediction of the flow and aerodynamic forces. The model predicts the flow field and the lift and drag forces on the airfoil. The non-linear governing equations for the flow are solved using numerical methods. The Weis-Fogh clap-and-fling mechanism is studied and compared with previous CFD results.